feat: Introduce TO_<NUM> library functions

This commit introduces the `TO_<NUM>` library functions, which under the
hood use the already exisiting and tested `<NUM>_TO_<NUM>` library functions.

libs/stdlib/iec61131-st/to_num.py

@@ -0,0 +1,87 @@
+f = open("to_num.st", "w")
+
+types = [
+    "SINT",
+    "USINT",
+    "INT",
+    "UINT",
+    "DINT",
+    "UDINT",
+    "LINT",
+    "ULINT",
+
+    "REAL",
+    "LREAL",
+
+    # "BIT",
+    # "BOOL",
+    # "BYTE",
+    # "WORD",
+    # "DWORD",
+    # "LWORD",
+
+    # "STRING",
+    # "WSTRING",
+
+    # "TIME",
+    # "LTIME",
+    # "DATE",
+    # "LDATE",
+    # "DT",
+    # "LDT",
+    # "TOD",
+    # "LTOD",
+]
+
+generic = """(********************
+*
+* Converts any other numerical value to {0}
+*
+*********************)
+FUNCTION TO_{0}<T: ANY_NUM> : {0}
+    VAR_INPUT
+        in : T;
+    END_VAR
+END_FUNCTION
+"""
+
+generic_impl = """(********************
+*
+* Converts {0} to {1}
+*
+*********************)
+FUNCTION TO_{1}__{0} : {1}
+    VAR_INPUT
+        in : {0};
+    END_VAR
+
+    TO_{1}__{0} := {0}_TO_{1}(in);
+END_FUNCTION
+"""
+
+generic_impl_same = """(********************
+*
+* Converts {0} to {1}
+*
+*********************)
+FUNCTION TO_{1}__{0} : {1}
+    VAR_INPUT
+        in : {0};
+    END_VAR
+
+    TO_{1}__{0} := in;
+END_FUNCTION
+"""
+
+for type_from in types:
+    f.write(generic.format(type_from))
+    f.write("\n")
+
+    for type_to in types:
+        if type_from == type_to:
+            f.write(generic_impl_same.format(type_from, type_to))
+        else:
+            f.write(generic_impl.format(type_from, type_to))
+
+        f.write("\n")
+